Plus, unlike shares of Bank of America, a Ferrari can be driven around with the top down on a sunny day.

But the prices of collectible cars may be as much a function of the excess capital held by the wealthy than the inherent value of cars. With other investments generating such low returns, cars and other collectibles become more attractive.

Take, for instance, the two charts below. The first (courtesy of Gooding and Sports Car Market Magazine) shows the prices for the most expensive cars ever sold at auction:

1985 — $2,788,513 a 1934 Alfa Romeo Tipo B Monoposto.

1985 — $3,424,490 for a 1957 Aston Martin DBR2.

1987 — $9,800,000 for a 1931 Bugatti Type 41 Royale

2008 — $10,894,400 for a 1961 Ferrari 250 SWB California Spyder

2009 — $12,402,500 for a 1957 Ferrari 250 Testa Rossa

2011 — $16,390,000 for a Ferrari 250 Testa Rossa Prototype

The second (courtesy of Emmanuel Saez) shows the average income of the top 0.1%, or the group most likely to be buying multi-million-dollar cars

Average Income of Top 0.1%

1985– $1.2 million

1987– $1.6 million

1998 — $3.1 million

2007 — $4.4 million

2008 — $3.9 million

Both charts show that the real quantum leap in wealth and car prices was between 1985 and the mid-2000s, which was also when the stock market boomed (though the 1987 Bugatti sale was more of a prelude than proof of the boom).

What’s interesting is that while the top incomes have remained roughly flat since 2008, the price of the most expensive car has continued to soar. That may be due to rising wealth overseas and global demand for collectible cars from buyers outside the U.S.

But it may also suggest that the top prices for collectible cars may be de-coupling from the stock market and top incomes.

What do you think the auction price of the most expensive car will be in 2020?